One micron represents a length of

The correct answer is (a) 10-6 cm.

A micron (μm) is a unit of length equal to one millionth of a meter (10-6 m). It is also known as a micrometer. Micron is a common unit of measurement in biology and medicine, where it is used to measure the size of cells, bacteria, and other small objects.

Option (b), 10-4 cm, is equal to one thousandth of a millimeter (10-3 mm). Option (c), 1 mm, is equal to one thousandth of a meter (10-3 m). Option (d), 1 m, is equal to one meter.